Process of making black dyes.



No. 787.824. Patented April 18, 1905.

UNITED STATES ATENT Fries.

RENE BOHN, OF MANNHEIM, GERMANY, ASSIGNOR TO THE BA DISOHE ANlLlN & SODA FABHIK, OF LUDiYlliSllAFliN-t)NllllG-RHINE, (iER- MANY, A CORPORATION OF BADEN. I

PROCESS OF MAKING BLACK DYES.

SPECIFICATION forming part of Letters Patent No. 787,824, dated April 18, 1905.

Application filed .pril 29, 1904. Serial No. 205,587.

II'7I/HII/ 4] (WI/W170! l solves in water, yielding a. dull-fuchsina-ed 5 Be it known that l, Rana Boux, doctor of solution which on the addition of caustic philosophy and chemist, a citizen of the Swiss soda becomes violet. it yields a blue-violet Republic, residing at Mannheim, in the (hand solution in concentrated sulfuric acid.

l)uchy ot Baden. ('rrerman Empire, have in- Example .2: Dissolve one hundred (100) vented new and useful Improvements in Black parts of the sodium salt of metauilic acid in 55 l yes and Processes of .\lal ing the Same, of four hundred (shill) parts of water and add which the following is a specification. E thirty (30) parts of boric-acid crystals and two .\ly invention relates to the production of hundred (200) parts ol naphthazarin-paste I0 coloririg-matters trom rumhthazarin. l containing about lilty (51)) percent. oi naphlu the specilication ot Letters Patent No. thazarin. Stir the whole at a temperature of 60 6 1L613), dated August 22, 189$), l have deabout twenty-live degrees ceutigrade U) scribed the production of blue-black coloringfor from about thirty (30) to forty (to) hours,

matters by condensing imphthazarin with aroat the end of which time the deep-brown mix- 5 matic amins and afterward sult'onating the l ture, which during the lirst few hours becondensation products. lhave now discovered comes viscous and homogeneous, is completely 5 that eoloring-matters can be obtained by disoluble in water. Then treat the whole with rectly condensing naphthazarin, while susa saturated solution ol common salt, lilter, pended in water and in the presence of boric wash with more salt solution, and press and 0 acid,withthesultonicacidsotaronniticamins. dry the coloring-matter, which is thus oblhe coloring-matters obtained in this manner tained as a violet-brown powder. its solution 7 yield shades which on treatment with a biin water is deep red and turns violet-blue on chromate become deep blue-black. the addition of caustic soda. it yields a red- .lhe products of the process accordingto my dish-violet solution in concentrated sulfuric 5 invention are included among those claimed acid.

generically in the above-mentioned Letters Example 3: Dissolve one hundred and 75 Patent No. 631,613. twenty (P) parts of the sodium salt of 2.5-

llhe following examples will serve to furimphthylamin sult'o-acid in seven hundred ther illustrate the nature of my invention, (700) parts of water and add forty (40) parts 5 which, however, is not limited to these exot boric-acid crystals and two hundred (200) amples. The parts are by weight: parts ot naphthazarin-paste containing about 80 Example 1: Mix together two hundred lit'ty (51)) percent. of naphthzmirin. Stir the (201)) parts of naphthazarin in the form of a whole at a temperature of about twenty-live lit'ty (51) per cent. paste, one hundred (100) degrees centigrade l U.) tor from about parts of commercial sodium sult'auilate coir thirty (30) to forty (40) hours until it is con1- taiuing eighty per cent. of the pure. completelysolublein water. 'lreatthcwhole witha 5 pound, four hundred H00) parts of water, saturatlalsolutionolcommon salt, lilter, wash and twenty (20) parts of crystallized boric with more salt solution. and press and dry the acid. Stir this mixture well for from t'ortycoloring-matter, which is thus obtained as a eight (*8) to seventy-two (72) hours, maiubluish-brown powder. Its solution in water taining it at a temperature of from twentyl is violet-red and turns violet-blue on the ad- 9 live (25 to thirty degrees centigrade, (30 O.) l dition of caustic soda. it yields a blue-violet \Yhen the reaction is complete. (which is the solution in concentrated sulfuric acid. case when a test portion is completely soluble The processes for dyeing with these color- 45 in water,) pour the mixture into lit'tecn huning-matters may be the same as those which dred (1,500) parts of concentrated salt soluare used for dyeing with naphthazarin.

'lhis coloring-matter is a brown lt dis- 7 instead of ordinary naphthazarin (obtainable trom l.5-dinitro-naphthalene) the coloring-matter obtained from LS-dinitro-naphthalene according to the specification of Let- I 2. The process for the production of colorters Patent No. 661,438 can be used, and in- I ing-matter by condensing naphthazarin With stead of sulfanilic acid equivalent quantities l metanilic acid. of sulfo-a-cids of other aromatic amins can be l In testimony whereof I have hereunto set 5 employed and similar coloring-matters be obmy hand in the presence of tWo subscribing 5 tained. Witnesses.

Now what I claim is- RENE BOHN. 1. The process for the production of color- Witnesses:

ing-matters by condensing naphthazarin with ERNEST G. EHRHARDT,

10 a sulfo-acid of an aromatic amin. J. ALEO. LLOYD. 

